In recent years, an HDMI has been and is being popularized as a communication interface which transmits a digital image signal, that is, a non-compressed (baseband) image signal (hereinafter referred to as “image data”) and a digital sound signal (hereinafter referred to as “sound data”) associated with the image signal at a high speed, for example, from a DVD (Digital Versatile Disc) recorder, a set top box or some other AV source (Audio Visual source) to a television receiver, a projector or some other display apparatus (refer to, for example, Patent Document 1).
As regards the HDMI, a TMDS (Transition Minimized Differential Signaling) channel for transmitting image data and sound data at a high speed unidirectionally from an HDMI source (HDMI Source) to an HDMI sink (HDMI Sink), a CEC line (Consumer Electronics Control Line) for carrying out bidirectional communication between an HDMI source and an HDMI sink and so forth are prescribed. Patent Document 1: Japanese Patent Laid-Open No. 2006-319503